A long, narrow cut in the earth; a ditch; as, a trench for draining land.

Mortimer.

2.

An alley; a narrow path or walk cut through woods, shrubbery, or the like.

[Obs.]

In a trench, forth in the park, goeth she.
Chaucer.

3. Fort.

An excavation made during a siege, for the purpose of covering the troops as they advance toward the besieged place. The term includes the parallels and the approaches.

To open the trenchesMil., to begin to dig or to form the lines of approach. Trench cavalier Fort., an elevation constructed (by a besieger) of gabions, fascines, earth, and the like, about half way up the glacis, in order to discover and enfilade the covered way. -- Trench plow, ∨ Trench plough, a kind of plow for opening land to a greater depth than that of common furrows.